Once, the daily White House press briefing was a pretty pedestrian affair. It's become more eventful under the Trump administration. And today it was rather extraordinary. White House Spokesman Sean Spicer tried to warn Russia that its alliance with Syria put that country quote, "on the wrong side of history." And that's where Spicer found himself a moment later when he suggested wrongly that Hitler never used chemical weapons.

Of course any argument that drags in Hitler is likely to be dangerous, and this time was no exception. Spicer later apologized, saying his remarks were insensitive. NPR's Scott Horsley was there in the briefing room. He joins us now to talk more about this. Hey there, Scott.

SCOTT HORSLEY, BYLINE: Hi, Audie.

CORNISH: So Spicer was supposed to be talking about last week's apparent sarin gas attack in Syria. Give us the context. How did he end up talking about Hitler?

HORSLEY: Yeah, Spicer was really trying to argue that Russia should rethink its alliance with Syria's Assad regime after that regime went so far as to gas its own people in such a horrific way. But in trying to underscore the severity of last week's attack, Spicer reached back for a historical yardstick, and it wasn't a good one. Let's take a listen.

(SOUNDBITE OF ARCHIVED RECORDING)

SEAN SPICER: We didn't use chemical weapons in World War II. You know, you had a - someone as despicable as Hitler, who didn't even sink to the - to using chemical weapons. So...

HORSLEY: That left reporters in the room and certainly people watching on television scratching their heads because it seemed like Spicer was overlooking the millions who died in Nazi concentration camps.

CORNISH: Right. And a reporter did ask Spicer to clarify his remarks, right? What happened?

HORSLEY: Yeah. In fairness, I mean anybody can misspeak when they're speaking extemporaneously for long periods of time, and that certainly includes Sean Spicer. So a reporter tried to give the press secretary a do-over, asking Spicer to clarify. And you know, it just made matters worse. Here's Spicer trying to explain why Hitler's murderous gas was somehow different than Syrian President Bashar al-Assad's.

(SOUNDBITE OF ARCHIVED RECORDING)

SPICER: I think when you come to sarin gas, there was no - he was not using the gas on his own people the same way that Assad is doing. I mean there was clearly - I understand your point. Thank you.

UNIDENTIFIED WOMAN: I understand your point.

SPICER: Thank you. I appreciate that. There was not - in the - he brought them into the - to the Holocaust center, and I understand that. But I'm saying, in the way that Assad used them, where he went into towns, dropped them down to innocent - into the middle of towns. It was brought - so the use of it. I appreciate the clarification there. That was not the intent.

HORSLEY: You know, the reporter tried to give Spicer a lifeline, and he just used it to tie himself up in knots.

CORNISH: What's been the reaction outside the briefing room?

SPICER: It was swift and pretty severe. The Holocaust Museum, which is not far from the White House here in Washington, took Spicer to task on Twitter. The museum posted some video of what U.S. troops discovered when they liberated the Nazi death camp at Buchenwald.

The Anne Frank Center for Mutual Respect went further, saying Spicer ought to be fired for engaging what they called Holocaust denial. Democratic House Leader Nancy Pelosi also piled on, saying while Jewish families across the country were celebrating Passover, the chief spokesman of the White House was downplaying the horror of the Holocaust.

CORNISH: In the meantime, there have been some apologies out of the White House, right?

HORSLEY: That's right, Audie. First, Spicer put out a written statement, which really didn't diffuse the controversy. But later this evening, he went on CNN to try to make things right. He did apologize, and he said his comments in the briefing were a mistake.

(SOUNDBITE OF ARCHIVED RECORDING)

SPICER: I'm not, you know, in any way standing by them. I was trying to draw a comparison for which there shouldn't have been one. It was insensitive and inappropriate. I should have stayed focused on the Assad regime and the dangers that they have brought to their own people and the terrible atrocities they did. And to drag any other comparison into this was not appropriate.

HORSLEY: Now, Audie, I should say this is not the first time the White House has found itself in a pickle like this. The president put out a statement on Holocaust Remembrance Day his first week in office where he somehow forgot to mention the Jews who died at the hands of the Nazis.